Alarm-valve for steam-boilers



UNITED STATES 4PATENT OFFICE.

SELAH DUSTIN, OF DETROIT,

MICHIGAN.

ALARM-VALVE FOR STEAM-BOILERS.

Specification of Letters Patent No. 28,165, dated May 8, 1860.

To all whom it may concern:

Be it known that I, SELAH DUSTIN, of Detroit, in the county of Wayne and State of Michigan, have invented a certain new and useful Improvement in Low-Tater and High- Steam Indicating Apparatus for Steam-Boilers; and I do hereby declare the following to be a full, clear, and eXact description of the construction and operation of the same, reference being had to the ac companying drawings, making a part of this specification, in which- Figure l, represents in section the apparatus in question arranged in an elevated steam chamber, and in side view on the right of said ligure it is represented as arranged in a separate though not elevated chamber. Fig. 2, represents a modification of the plan shown in Fig. l.

Similar letters of reference where they occur in the separate figures denote like parts in all of them.

My invention consists, in so combining, with an elevated, or separate chamber, into which water or steam may fiow from the boiler through a suitable pipe or passage, as the water line in the boiler rises above, or falls below a given line, a float and valve, or a ioat and valves, as that the float shall, by its upward force, when said chamber is supplied with water, close said valve or valves, and act, by its gravity, when unsupported by water in conjunction with the steam then in the chamber, in opening said valve or Valves, to allow the escaping steam to ring a bell, blow a whistle, or sound an alarm when the water is too low in the boiler.

To enable others skilled in the art to make and use my invention, I will proceed to describe the same with reference to the drawings.

A, represents a boiler, in which the proper water line is indicated at B.

C, is an elevated chamber, connected to the boiler, by a water pipe a, which may have its lower end slightly below the proper water line, and by a steam pipe whose lower end is at the proper water line. These two pipes a, lead into the chamber C, as shown in the drawing. It is not, however, actually necessary that there should be two pipes, viz a water, and a steam pipe (but I so prefer them separate from each other); for a single pipe which is a water pipe when the water is above a given line in the boiler, and a steam pipe when the water is below that given line, can be used, but not with so much reliability. In the chamber C, I ar range a steam chamber D, which has two openings c, c in it, the one c being of greater area than the other c.

d, is a rod or stem carrying two valves e, e', with differential areas, and which close and open respectively the passages c, c.

E, is a lever having its fulcrum at f. The valve stem cl, is connected to this lever, between its tulcrum, and its free end, said free end of the lever catching upon, a collar, or projection, or other suitable catch piece, on a rod F, to the lower end of which the float G is attached. This rod F as well as the valve rod d, is properly guided and supported, so as vto be free to move without binding.

From the steam chamber D, there is an escape passage z', ,through which the steam passes when the valves e, e, are open, and this escaping steam strikes against the pistons m of the steam wheel H, causing said wheel to revolve, and by its revolution brings a hinged clapper n in contact with a bell I, to sound an alarm. Instead however of this contrivance a` steam whistle, or any other alarm apparatus may be used.

The operation of this apparatus is as follows: Vhen, and so long as, the lower end' of the steam pipe b is covered by the water in the boiler, the pressure of the steam will force the water up through the pipe a, which fills, or partially fills the chamber C, raising up the float G, which in turn raises up the lever E. The raising of the lever E, moves up the valve stem CZ, and carries the two valves e, e against, or into their respective openings or seats c c', and thus the chamber D, is closed and held closed against the escape or egress of any steam through it, so long as the water remains in the chamber C, or the buoyancy of the float is greater than the differential pressure on the valves e e. But when the water in the boiler falls below its proper level, and exposes the lower end of the steam pipe b, the' steam will immediately rush into the chamber C, and the water will flow'back through the pipe a, into the boilerthe differential pressure on the valves e, e', together with the weight of the float G, both act to open the valves e, e', which makes a free passage for the steam to the external part of the chamber, and this escaping steam sounds the alarm that the water is below its proper height in the boiler. The moment that the supply of water tothe boiler is had, the float is again raised up by the lling of the chamber C, and the valves are closed.

On the right of Fig. 1, I have shown the chamber as separate from, but not elevated above the boiler. This indicating apparatus, may be removed at any convenient distance from the boiler, and beyond the reach of the engineer, so that he cannot meddle with it.

It may be in a room above the boiler, or one p the nature and object of my.invention,eand some of its modifications, what I claim as new and desire to secure by Letters Patent adjoinin it. This modilcation is the same in its actlon and operation as that shown and described as elevated, and the same letters of reference indicate the same parts as those above explained-the only difference being that in this case the stem F serves the triple purpose of stem F, lever E, and valve stem d, in the above described arrangement, and another dierence is that, in this latter case the separate chamber is always in immediate communication with the steam in the boiler, but the alarm does not act, until the water falls below its proper height, just asin the first described case.

In Fig. 2, I have shown another modification of this apparatus, which has but a single valve r but this valve is closed, and held closed by the upward pressure of the Hoat, and when that upward pressure ceases, or in other words, when the water falls below its proper level, the steam acts in conjunction with the weight of the float to open said valve, and allow the steam to escape and sound the alarm. The same principle of opening the valve or valves by the steam in conjunction with the weight of the float pervades the several modications, as also the Y same principle of closing the valve or valves,

' it is a simple change of mechanism only, the

elements of the operation being the same in all cases.

Having thus 'fully described and shown ,So combining withan elevated, or separate chamber, into which water or steam may flow from the boiler through a suitable pipe or passage as the water line in the boiler rises Q above or falls below a given height, a ioat J and valve, or a ioat and valves, as that the sELAH DUsTIN.

Witnesses A. B. SToUGHToN, THos.I-I. UPPERMAN. 

